31 March 2000

Mushroom compost might cut tail biting

OFFERING spent mushroom compost to finishing pigs minimises tail biting and improves liveweight gain by 50g a day.

According to Violet Beattie, researcher at the Agricultural Research Institute of Northern Ireland, Hillsborough, tail biting costs a 100-sow unit £3000 a year in partial carcass condemnations.

"Tail biting leads to abscesses; 14% of partial carcass condemnations occur because of abscesses and, of these, 32% are the result of tail biting.

"The £3000 carcass condemnation cost does not take account of a 25% slower growth rate in tail-bitten pigs and extra labour required to remove them from pens," Dr Beattie told the conference.

Her research looked at whether adding 15kg/t of salt to a cereal/ soya finisher ration or providing access to spent mushroom compost had any effect on tail biting incidence.

"Anecdotal evidence suggests that tail biting may occur as a result of inadequate levels of diet salt. But our research showed no difference between pigs on control and high salt diets – tail biting incidence was 3-4%."

But in pigs offered spent mushroom compost, from which the surface casein layer was removed, tail biting was eradicated. "Pigs rooted in the spent mushroom compost, offered on 6ft x 2ft racks, spending less time nosing pen-mates and pen fixtures."

Feed intake also rose by 0.16kg a day and liveweight gain by just less than 50g a day in pigs offered compost for rooting. "Intakes and growth rates tend to be higher when pigs can root, as dominant pigs spend less time near troughs, allowing subordinates to feed.

"Offer compost at a rate of 0.5kg a pig a day on a wire mesh grid which can be suspended using baler twine. Cost works out at 70p a pig over the finishing period." &#42

Offering finishing pigs spent mushroom compost to root in pays dividends, says Violet Beattie.